I really get perturbed at men who act as if they are doing the only "real" work because the woman is at home taking care of the kids. This is a mentality that unfortunately was pushed off on most men and women for a long time, but I believe it is very wrong.
He wants to complain that you’re not contributing, but what does he think he would pay for the same service if you weren't there? First off he has a 24/7 baby sitter. So let’s figure in the cost of a live in nanny who very selflessly never takes time off. He also has a housekeeper who provides all his home cleaning needs and again very selflessly never takes time off. Let’s not forget that he is putting down the one person providing these services with no time off. Does that sound right? Does it sound like he has a leg to stand on? I don't think so. There are plenty more benefits he receives from you as a stay at home mom, that he doesn't pay a dime for, yet would cost a bundle if he did pay. You are the one with the little ones, teaching them and guiding them each day throughout the day while he is making an income. You do the shopping for him (I assume). You also take care of the colds, the tummy aches, trying to figure out the many different cries coming from your little ones, while he sits at work making money for far less work. The list can go on and on.
Women provide more services then most men could ever dream of, yet they are the most underappreciated for those services, which are given freely and usually without any real break. Then they wonder why we are stressed out, why we ask for help, why we get angry when they can't pitch in to take a small bit of the load off our shoulders, why we are cranky, bitchy, tired, and worn down. As they see it you get to stay at home all day and have fun with the darling little angles, having fun and doing no work, but there image is completely false. You have every right to ask for help, to be stressed, tired, and any other of the myriad of feelings that come from being over worked, unappreciated and not paid. Taking care of house home and kids is not all fun and games, and it "contributes" a lot more then he will ever understand, and a lot more then his income ever will. Even if he paid for all those services from a professional, he still won't get all the benefits he has from a loving mother and wife, stay at home or not.
As to your business, I wonder how well he would have faired had he tried to care for two babies and do all the duties of his job at the same time. Not well, I assume. He certainly wouldn't be the big success he claims to be, had he provided all the care you provide while working on his paid job.
The advice I would give is pretty much what others have posted. Sit him down when he is off work and not busy playing or watching TV. I do a lot of my talking before we go to sleep at night, because there are fewer distractions, and the kids are not around. Explain to him that taking care of the kids is a lot more work then he realizes, and that you are stressed out, and tired and could really use a little loving support and help. Remind him that these are his kids too, and this is his home too, that you appreciate his work and contribution, but that doesn't release him from the responsibility he should share in caring for the kids and the household. List out for him all the many jobs that you have to do everyday, all day without any pay, without any break, and with a husband that puts you down about lack of contribution, when in reality you are contributing much more then he gives you credit for. Tell him this is an all day everyday job that never goes away, and is very stressful especially when it isn't appreciated and he never gives any help. Add in anything else that you feel is valid and should be included in the discussion, and let him talk too, just not in a condescending manner.
Back several months ago I had to have a similar discussion with my husband just because I was at the end of my rope. My husband is helpful though, and he appreciates what I contribute as a mother. My problem at the time was that I was taking a full load of very time-consuming classes, taking care of the kids, and trying to take care of the home. I needed help because it was just too much for me to handle and my husband wasn't doing near enough to help. I explained how stressed I was, how much time my classes were taking from everything else, that dealing with everything with the kids while I'm working on school work was making the school work take far longer than it had too, and that I couldn't keep going like that without some help. I told him that he would at least need to take care of the kids while I'm working on schoolwork. We managed some compromises, from that talk, I was able to put more effort into my quickly falling apart home, I was better able to care for my kids without snapping at their every mess or tantrum, and I was able to keep my sanity. And keep in mind, that staying home with the kids all day as you are is very stressful all in itself. You need time away from the kids, time for yourself, time for others, time to socialize with adults, and time away just to keep your sanity. Let him stay with them all weekend sometime with no real break and see how he likes it.
Getting some kind of family counseling, or marriage counseling is probably a good idea too. Or maybe some sort of weekly parenting group where both of you can get other input from other parents in a less intimidating manner then might occur from a counselor.
OK I'll shut my trap now. Sorry I went on so long, this is just an issue that is very important to me, and I had a lot to say.
Good luck, and bless you and your family. I hope everything works out and Hubby learns to appreciate the wonderful gift he has been given from you and your family.